1. Field of the Invention
The present invention relates to a wind direction adjusting device of an air conditioner.
2. Description of the Related Art
FIGS. 12 to 14 relate to the conventional ceiling-embedded cassette type air conditioner and its blow-off opening portion which is disclosed in e.g., Unexamined Japanese Utility Model Publication No. Hei. 6-28517. FIG. 12 is a longitudinal sectional view of the ceiling embedded cassette type air conditioner equipped with a glazed panel, and FIGS. 13 and 14 are longitudinal sectional views of a blow-off opening portion of the decoration panel.
In these figures, reference numeral 4 denotes a decoration panel attached to the lower surface of an air conditioner unit body 2. An opening portion 3 of a ceiling 1 is covered with the decoration panel 4. Reference numeral 5 denotes an sucking opening portion provided at a center portion of the decoration panel 4. Reference numeral 6 is one of blow-off opening portions provided on both sides of the decoration panel 4. Reference numerals 7 and 8 denote blower and a heat exchanger, respectively which constitute a unit body 2. The unit body 2 is secured to a hanger bolt 22 through hanging metal fittings 21 provided on the side of the unit body 2.
FIGS. 13 and 14 are enlarged views of the structure of a blow-off opening portion 6 provided on the decoration panel 4. In these figures, reference numeral 13 denotes a wind direction deflecting plate provided in a wind path 10 for deflecting blown-off wind vertically. The outer wall 18A of the wind path 10 is formed along a direction 23 making an angle .alpha. with a horizontal blowing direction PO1 and its longitudinal section is linear. The angle .alpha. has a sign of + when counterclockwise rotation is formed around a direction vertical to paper and is set at an angle of 5.degree. or less.
An explanation will be given of the operation of the conventional air conditioner. In the conventional air conditioner, the blow-off opening portion is structured as described above. In operation, when the blower 7 is driven, the air in the room is sucked from the sucking opening portion 5. The sucked air is cooled during cooling and heated during heating by the heat exchanger 8. The cooled or heated air blows off from the blow-off opening portion 6 into the room along the wind path 10. The vertical direction of the blown-off wind is adjusted by the wind direction adjusting plate 13. With reference to the plane in parallel to the ceiling plane 1, the blow-off angle of 40.degree. is set at a horizontal blowing PO1 and that of 60.degree. is set at downward blowing PO4. The angle of horizontal blowing PO1 is a critical angle where the blowing wind does not flow along the decoration panel 4 and the ceiling plane 1. The angle of the downward blowing PO4 corresponds to the direction of the path of the blow-off opening portion 6.
During a cooling operation, when the blow-off angle is set at the horizontal blowing PO1 where the blown-off wind is separated from the ceiling 1, a portion 24 of the cooled air blown off flows along the outer wall 18 and goes out from the blow-off opening portion 6. The air advances along the outer lower surface 4A of the glazing panel while being mixed with indoor air 19. On the ceiling plane 1 at the end of decoration panel 4, the blown-off cooled air 24 merges with the indoor air 19. At this point, the temperature of the blown-off cooled air 24 has become higher than immediately after it has gone out from the blow-off opening portion 6, thereby preventing condensation because the indoor air 19 does not become lower than the dew point temperature.
If the wind direction deflecting plate 13 is set in the horizontal blow-off direction PO1 as shown in FIG. 14, the distance between the inner wall 18B of the blow-off opening portion and the rear end of the wind deflecting plate 13 becomes short so that the resistance against the wind path will be increased. Thus, the amount of wind flowing between the inner wall 18 of the blow-off opening portion and the wind direction deflecting plate 13 will be reduced. As a result, high-temperature and high-humidity indoor air 19 will be involved in the blow-off opening portion so that it flows in contact with the negative pressure side of the wind direction deflecting plate 13. Thus, owing to the heat conduction from the pressure side of the wind deflecting plate cooled by the blown-off wind, the temperature of the negative pressure side will become a dew point or lower, thus generating condensation.
In the conventional wind direction adjusting device, which is structured as described above, the wind speed distribution in the wind path 10 is not uniform. Since the wind path 10 is bend at right angles, under the influence of centrifugal force, the wind speed becomes higher at a more outer side of the unit body. Thus, the flow reaches the blow-off opening portion 6 along the wind path wall on the outer wall side by the Coanda effect. In this case, even if the wind direction deflecting plate intends to deflect the wind direction, since the deflecting direction of the flow is influenced by the side of the higher wind speed, it is restricted by the shape of the wind path wall along which the flow at a higher wind speed goes. This hinders the controllability of wind direction from being enhanced.
Because the wind speed at the blow-off opening portion distributes toward the side of the outer wall, the amount of wind directed to the side of the inner wall decreases and the blown-off flow does not almost flow toward the negative pressure side of the wind direction deflecting plate 13. In this state, when the blow-off angle is set to the horizontal blowing of PO1 during cooling, the direction of the wind direction deflecting plate 13 is greatly deflected from the direction of the wind path in the blow-off opening portion 6. Thus, the blown-off air flow at the negative pressure side of the wind direction deflecting plate is separated to involve high-temperature high-humidity indoor air 19. Further, since the wind deflecting plate 13 is cooled to the due point or lower by the cooled air abutting on the pressure surface side of the wind direction deflecting plate 13, the indoor air 19 abutting on the negative pressure surface side of the wind direction plate 13 produces condensation.
In order to prevent dew drop due to the condensation on the wind direction deflecting plate, it is necessary to implant fiber on the entire surface of the wind direction deflecting plate to provide water keeping capability. This leads to an increase in the production cost, and impairs the good appearance because smudges applied to the fiber cannot be removed.
A part of the blown-off cooled air flows along the outer bottom surface 4A of the decoration panel 4 while it involves the indoor air and increases the temperature. For this reason, the condensation occurring on the outer side of the blow-off opening portion is prevented in such a manner that the outer bottom surface 4A of the decoration panel 4 is not lowered to the dew point or lower. The ceiling, however, is necessarily cooled. Because of the minute condensation thus generated, the ceiling resulted in a wet state. This leads to a smudging phenomenon in which minute dust floating in the blown-off air flow is applied onto the ceiling.
Particularly, both ends of the wind direction deflecting plate 13 have to be shaped to conceal the inside of the blow-off opening portion 6 from the viewpoint of design. Both ends of the wind direction deflecting plate 13 and the wall of the blow-off opening portion 6 opposite thereto are caused to be adjacent to each other to the degree that they are not brought into contact with each other. As a result, the sufficient amount of wind cannot be assured so that the ambient indoor air 19 is likely to be involved, thereby necessarily generating condensation.